Proprietary dental casting alloys and experimental gold-silver- copper-alloys containing up to four percent platinum and 20 percent palladium will be studied to obtain an improved understanding of the relationships between microstructure, properties and the hardening mechanism. The purpose of this study is also to identify new and useful compositions lying outside the current range of proprietary compositions. Specimens will be prepared in solution treated and various age hardened conditions. Ordering will be evaluated by X-ray diffraction while precipitation will be followed by both diffraction and metallography. The rates of ordering and precipitation will be compared with the rate of hardening as determined by identation testing.